This invention relates to a sealed head access area (HAA) enclosure for a liquid-metal-cooled fast-breeder power reactor and to a sealant joint for use therein.
It has been postulated that, as a result of a core disruptive design basis accident, some sodium and gaseous products from the reactor would egress from the reactor vessel into the reactor containment building which consequently would become heavily contaminated with radioactivity. If such a contingency is deemed a credible accident a guard enclosure sealing the volume immediately above the reactor vessel head from the remainder of the containment vessel would be indicated. The sealed HAA enclosure would provide the environment, structural support and access to the reactor for electrical wiring, gas plumbing, refueling, inspection surveillance and maintenance services. The core disruptive accident effects of the accident may cause a pressurization of the sealed HAA due primarily to sensible heat from the reactor. The sealed HAA must contain any egress products under this pressurization condition. In addition to this primary function, the sealed HAA must be compatible with other reactor components and operations.
The present invention will be described herein specifically as applied to the Clinch River Fast Breeder Reactor. The specific embodiment of the invention disclosed is a parallel design option for that reactor and may not be actually incorporated in the plant as built.